Fix frequency verb invalid frequency behaviorjellyfish_10.0.1jellyfish/10.0.110.0.1

The frequency verb was not checking if a frequency corresponds to the
frequency band step the binding provides to users, add logic to do so
and return an error if the frequency is invalid.  While this is a
change in behavior, it is believe it should not impact users, as the
binding is intended to reflect user facing radio application usage.

Additional tweaks:
- fix error invalid frequency error message in reply JSON.
- add the same band limit checks to the null implementation's
  frequency setting function that the other implementations do.
- fix a couple of issues in README.md; the "rds" verb was missing,
  and the value key name for the "frequency" event was incorrect.

Bug-AGL: SPEC-3620

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: I2adfc10448546264110f6d854f02d677087f1e47
(cherry picked from commit 8958a8a3e98085c60c9cd803395be157e78e3565)

1 files changed, 4 insertions, 0 deletions

diff --git a/binding/radio_impl_null.c b/binding/radio_impl_null.c
index 8c28bca..a90835b 100644
--- a/binding/radio_impl_null.c
+++ b/binding/radio_impl_null.c
@@ -120,6 +120,10 @@ static uint32_t null_get_frequency(void)
 
 static void null_set_frequency(uint32_t frequency)
 {
+	if(frequency < known_fm_band_plans[bandplan].min ||
+	   frequency > known_fm_band_plans[bandplan].max)
+		return;
+
 	current_frequency = frequency;
 
 	if(freq_callback)